Sterilizing means



Feb. 13, 1934. c. R. MEITZLER STERILIZING MEANS I 3 Sheets-Sheet 1 FiledOct. 30 1931 Feb. 13, 1934. Q R MEWZLER 1,946,804

STERILIZING MEANS Filed Oct. 30, 1931 3 Sheets-Sheet 2 3 Sheets-Sheet 3C. R. MEITZLER STERILIZING MEANS Filed 0011. 30

Feb. 13, 1934.

51 A IWyM,

Patented F eb. 13, 1934 UNITED STATES PATENT OFFICE STERILIZIN G MEANSRochester, N, Y.

Application October 30,

8 Claims.

This invention relates to sterilizing means, and more particularly tosterilizers adapted for use in dental oliices and similar places.

The present invention is in the nature of an improvement over thesterilizer disclosed in my co-pending application, Serial No. 478,338,filed August 28, 1930. In the sterilizer of said copending application,I have provided a water tank which communicates with the sterilizingtanks, and a removable water container for supplying water to the watertank when the water therein falls below a predetermined level. I havealso disclosed, in such co-pending application, heating means for thesterilizing tanks and means for automatically disabling such heatingmeans when the water in the water tank falls below a predeterminedlevel, the heating means being restored to operative condition when thewater level in the water tank is restored to normal. While thesterilizer of my co-pending application is highly efiici nt, I find thatit can be rendered even more efiicient by providing means for supplyingwater to the water tank from a source exterior thereto, such as thewater supply pipe of a dwelling or office building, the admission ofwater to the tank being regulated so as to maintain the water at apredetermined level therein, the regulating means serving also todisable and enable the heating means for the sterilizing tanks.

One of the main objects of my invention is to provide a sterilizingmeans of the character stated provided with a water supply pipe openinginto the water tank, the admission of water from this pipe to the tankbeing regulated by means responsive to the water level in the latter. Afurther object is to provide means actuated by the regulating means fordisabling and enabling the heating means for the sterilizing tanks.Another object is to provide a structure in which the regulating meansand associated features are so related as to produce a compact structureparticularly well adapted for use with sterilizers. It is also an objectof my invention to provide simple and eflicient means for maintainingthe water in the sterilizing tanks at the most elficient level forsterilizing purposes. Further objects and advantages of my inventionwill appear from the detailed description.

In the drawings:

Figure l is a fragmentary vertical sectional view through a sterilizer,taken from front to back thereof, illustrating my invention as applied,parts being broken away i v V Figure. 2. is a section takensubstantially on 1931. Serial No. 571,953

line 2-2 01' Figure 1, on an enlarged scale, parts being shown inelevation;

Figure 3 is a section taken substantially on line 3-3 of Figure 2; and

Figure 4 is a diagram of the connections of the heating units for thesterilizing tanks.

I have illustrated my invention, by way of example, as applied to asterilizer comprising a cabinet 1 having a removable top 2 provided withsuitable openings therethrough for receiving and supporting sterilizingtanks 3 and 4, tank 3 being adapted for reception of instruments to besterilized and tank 4 being adapted for reception of towels, dressings,and similar articles to be sterilized. The construction of the cabinetand the cover therefor, as well as of the tanks 3 and 4, is similar tothat of my above identified co-pending application and need not bedescribed here in detail, it being suflicient to note that suitablemeans is provided for supporting the sterilizing tanks.

Each of the sterilizing tanks has associated therewith a heating unit 5(Figure 4) this unit comprising two pairs of resistance elements a andb, the elements a and b of each pair being connected in multiple.Resistance element a' of one pair is connected in series with resistanceelement b of the other pair, and with a thermostat 6 of known type. Thisthermostat acts, when the water in the sterilizing tank has been heatedto a predetermined high temperature, to open the circuit of the elementsa and b asso-' ciated therewith, thus reducing the heating capacity ofthe unit 5. Pilot lights '7 are connected across the respective heatingunits 5, and the several circuits for these units have fuses 8interposed therein, these fuses being carried by a fuse block 9 of knowntype. Manually operated switches 10, of suitable type, are provided forcon trolling the circuits of the heating units 5. Ourrent is supplied tothe heating units by mains 11 and 12, and a mercury tube switch 13 isinterposed in main 11. Normally the switch 13,is closed so that byclosing the switches 10 the heating units 5 may be rendered operative,selectively. If the water in the sterilizing tanks falls below a safelevel, the switch 13 is automatically opened, thus disabling the heatingso as to preventinjuryto the sterilizer-tanks, such as would occur ifsuch tanks were heated with insufficient or no water therein. Thevarious connections of the heating units are described in more detail inmy co-pending application previous]; referred to, and need not bedescribed here in greater detail, it sufiicing to note that the switch13 is a main control switch for disabling and enabling the heatingunits.

Conveniently, the heating units comprise two members 5a (Figure 1) ofknown type, each of these members including one pair of resistanceelements a and b suitably mounted upon and enclosed by insulatingmaterial. Members 5a are pressed firmly against the bottoms of thesterilizer tanks by pressure plates 14. Each of the plates 14 isprovided, adjacent each end thereof, with a depending boss 15 suitablyrecessed for the upper end of a pressure screw 16 which threads througha boss 17 of a channel bar 18, the ends of which rest upon upturnedterminal elements of straps 19 secured to and depending from thesterilizer tanks. This provides simple and efiicient means for securingthe heating units in operative relation to the sterilizer tanks. A tanksecuring strap 20 in the form of a double U is suitably secured to lugs21 carried by top 2 of the cabinet. This strap passes about and beneaththe sterilizer tanks and receives screws 22 passing therethrough, thesescrews threading into the chamiel bars 18 and cooperating therewith andwith straps 19 to anchor the sterilizer tanks to the top of the cabinet.Each of the sterilizer tanks has associated therewith a suitable coverand means for opening and closing the same, which need not beillustrated nor described in detail here, it being sufficient to notethat the sterilizers have suitable covers and operating means therefor.

A water tank 23 depends from top 2 of the cabinet adjacent the backthereof, this tank being conveniently formed integrally with the top. Acup-like receptacle 24 is suitably secured to, and depends from, thetank 23 at one end thereof, this receptacle communicating with the tankthrough an opening 25 therein. Receptacle 24 opens into the adjacent endof tank 23, through the bottom thereof, by means of an elbow 26extending from the receptacle remote from the upper end thereof, theupper end of this elbow being suitably secured to a boss 27 formed onthe tank and provided with an opening 28 into the tank. Receptacle 24 isprovided, at the bottom thereof, with an outlet or drain opening 29 and,a short distance from its upper end, with a nipple 30 defining an outletopening 31. This nipple is connected by a union 32 with a pipe 33 whichcommunicates, by means of suitable connections 34, with the sterilizertanks through the bottoms thereof. A nipple 35, which defines the drainopening 29, extends from the bottom of receptacle 24 and is suitablyconnected to a drain pipe 36, the forward end of which extends into thevalve casing 37 with which communicates connection 34 of the forwardsterilizer tank 3. The outlet from this latter connection 34 and theoutlet from the drain pipe 36 are controlled by suitable valves disposedwithin casing 37, such valves having stems 38 and 39 projectingforwardly of the casing. The casing 37 terminates, at-its lower portion,in a drain spout 40. Normally the valves are closed, and by opening thevalves the tanks and the receptacle 24 can be drained,

pipe 36 and the associated valve and spout 40. This provides means forconditioning the water preliminary to its entry into the sterilizertanks so as to eliminate or reduce the deposition of minerals therein.

Water is supplied to the tank 23 by means of a water supply pipe 41which is suitably connected to a source of supply of water underpressure, preferably the water supply system of a dwelling or oificebuilding. The pipe 41 is connected by a union 42 to a nipple 43 suitablysecured through the bottom of tank 23, adjacent one end thereof, in aknown manner. Nipple 43 depends from a fitting 44 of known type in whichoperates a valve 45, also of known type, for controlling admission ofwater to the tank. This valve is suitably connected to a link 46 pivotedat one end, at 47, in a bracket 48 extending upwardly from the fitting44 at one side thereof. The other end of link 46 is connected by aclevis structure 49 to one end of a lever 50 pivoted at 51 in a bracket52 extending upwardly from fitting 44 at the opposite side thereof. Afioat 53 is suitably connected at 54 to the other end of lever 50. Thisfioat is responsive to the water level in tank 23 and operates the valve45 so as to regulate admission of water to the tank in such manner as tomaintain the water therein at a predetermined level. An overflow nipple55 is suitably secured to the bottom wall of the tank and is connectedby a union 56 to a pipe 57 conveniently connected to the sewer. Theoverflow nipple 55 and pipe 57 prevent flooding in the event the valve45 fails to close properly when the water reaches the predeterminedlevel in the tank, which normal and predetermined level is indicated bythe line .ra:.

For the most efiicient operation of the sterilizers, it is importantthat the water in the sterilizer tanks be maintained at such a leveltherein that each of the sterilizer tanks contains only that amount ofwater which is most efficient for sterilizing purposes. This has theadvantage of expediting the sterilizing operation while also effecting amaterial saving in the fuel or electricity utilized for heatingpurposes, since the amount of water required to be heated at any giventime is the minimimu amount required for efficient sterilizing. Withthis object in view, the sterilizing tanks are so disposed relative tothe water tank that, when the water in the latter is at normal level,the amount of water in each of the sterilizing tanks is the minimumamount required for efficient sterilizing. In this connection, since thewater supply pipe 41 is conessary that there be an appreciable drop inlevel in the water tank, accompanied by a corresponding drop in waterlevel in the sterilizing tanks, before the supply of water in the watertank is replenished and again restored to normal level. I consider thisclose regulation of the water level in the tanks of considerableimportance as contributing materially to the efiiciency of thesterilizers.

The main control switch 13 is mounted in spring'clips 58 carried by amounting plate 59,

which plate is adjustably mounted by pin and slot means upon a baseplate 61 pivoted at 62 on a bracket 63 suitably secured to and depend--ing from the bottom of tank 23. Flexible leads 64 are connected to theterminals of the mercury tube switch 13, one of these leads being alsoconnected to a suitable terminal carried by a connecting block 65 whichis suitably mounted upon the bracket 63. The other terminal 64 isconnected to the positive main 11 of Figure 4 in a suitable manner. Theblock 65 also carries a terminal 66 which is suitably conneoted, in aknown manner, to terminal 67 to which lead 64 is connected, the terminal66 being connected by lead 110. to switches 10. In this manner theswitch 13 is connected in series with the positive main, as in Figure 4.By rocking the base-plate 61, the switch 13 is tilted to open orclosethe circuit, thus disabling or enabling the heating units or" thesterilizing tanks, in accordance with the water level therein.

A tube 68 is suitably secured through the bottom of tank 23 and extendsupwardly therein well above the normal water level. A connecting rod 69is slidable through tube 68. The lower end of rod 69 is suitablysecured, as by means of ,a set screw 76, in a clevis 71 which is pivotedat 72 to one corner of plate 61. The upper end portion of rod 69 isshaped to provide a hook'element '73 which engages over and about lever50. Rod 6.9 is thus connected to the lever for movement therewith. Whenthe water in tank 23 is at the predetermined and normal level therein,the switch 13 is in horizontal position, or closed, so as to completethe circuit therethrough. If the water in tank 23 falls materially belownormal level, float 53 is lowered, this causing downward movement of rod69 due to movement of lever 50 with the float. This movement of rod 69rocks plate 61 in a counterclockwise direction, as viewed in Figure 2,and tilts the switch 13 suificiently to open the circuit therethrough,thus disabling the heating units of the sterilizing tanks. The downwardmovement of float 53 results in opening of valve 45 and the admission ofwater to tank 23. When the water in this tank has been restored to itsnormal level, float 53 returns to normal position and rod 69 acts toreturn plate 61 to normal position, thus again closing the circuitthrough switch 13. Ordinarily, the normal water level will be maintainedin tank 23 and the switch 13 will remain closed. If the valve 45 shouldfail to open properly, or for any other reason the proper supply ofwater to the tank 23 is interfered with, and the water in this tankfalls materially below normal level, the switch 13 will be opened in themanner described, thus disabling the heating units of the sterilizingtanks and preventing injury to the latter such as would occur if theheating units remained in operation with an inadequate amount of waterin the sterilizer tanks.

The control switch 13 is operated by the means which regulates theadmission of water to the tank 23. This is advantageous since, underordinary conditions, the control switch is maintained in closed positionand the water in the tank is closely regulated so as to be maintained atthe most efficient operating level therein. In the event the water inthe tank 23 drops materially below the predetermined level therein, themeans for regulating the admission of water to the tank operates throughthe rod 69 and associated parts, to open the main control switch 13 inthe manner previously described.

The tank 23 is normally closed by a removable cover 75 having adepending flange 76 fitting about the upper portion of the tank. Thiscover gives ready access to the interior of the tank and to the partsdisposed therein, as desired or as conditions may require. The provisionof the pipes 33 and 36, in conjunction with the main valve casing 37 anddrain faucet40, and associated parts, is advantageous as facilitatingdraining of the tanks or of the receptacle 24, selectively.

What I claim is:

1. In sterilizing means, a sterilizing tank, heating means therefor, awater supply tank communicatingwith the sterilizing tank for supplyingwater thereto, means for supplying water to the water tank, meansresponsive to the water level in said water tank for regulating theadmission of water thereto and for normally maintaining the watertherein at a predetermined level, and means connected to and actuated bysaid regulating means for disabling said heating means when the water inthe water tank falls materially below said predetermined level, andenabling the heating means when the water in the water tank is restoredto operating level therein.

2. In sterilizing means, a sterilizing tank, electrical heating meanstherefor, a water supply tank communicating with the sterilizing tankfor sup-, plying water thereto, a water admission pipe opening into theWater tank, a valve controlling said pipe, float means responsive to thewater level in the Water tank and operatively connected to the valve formaintaining the water in said water tank at a predetermined leveltherein, a control switch for said heating means, and disposed beneaththe water tank, a tube opening through the bottom of said water tank andextending above the normal water level therein, and a connecting memberextending through the tube and connecting the float means to the switchfor opening and closing the latter in accordance with fall of the Waterin the water tank materially below said predetermined level andrestoration of the water in said water tank to normal level therein.

3. In sterilizing means, a sterilizing tank, electrical heating meanstherefor, a water supply tank communicating with the sterilizing tankfor supplying water thereto, a water admission pipe opening into thewater tank, a valve controlling said pipe, a lever connected to thevalve for opening and closing the latter, a float within the water tankand connected to the lever for regulating closing and opening of thevalve for maintaining the water in said water tank at a predeterminedlevel, a bracket depending from the tank, a control switch for theheating means pivoted on the bracket, a tube opening through the bottomof the tank and extending above the normal water level therein, and aconnecting rod slidable through the tube and connecting the lever andthe switch for opening and closing the latter in accordance with fall ofthe water in the water tank materially below said predetermined leveland restoration of the water in said water tank to normal level therein.

4. In sterilizing means, a sterilizing tank, a water tank, a receptacleextending below the water tank and receiving water from the latteradjacent the bottom thereof, a drain pipe extending forwardly from thelower portion of the receptacle, a pipe extending forwardly from theupper portion of the receptacle and opening into the sterilizing. tankfor supplying water thereto, andvalve means at the forwardlends of there* spective pipes for controlling the latter;

v5. In sterilizing means, a sterilizing tank, ae water tank, areceptacleextending below-the wa ter tank and receiving water from the latter adjacent the bottom thereof, a drain pipe extending forwardlyfromthe'lower portion of the receptacle, a pipe extending forwardlyfrom= the upperportion 01 the receptacle and opening intothe sterilizingtank for supplying water thereto, a valve casing at the forwardendsofand common to the pipes, said casing including a drain spoutextendingtherefrom, and valve means associated with the casing forselectively controlling the pipes.

6. In sterilizing-means, a sterilizing tank, heat-- ing means therefor,a water supply tank com miuiicating with the sterilizing tank forsupplying water thereto: and connected'to" an exterior" source of supplyof water under pressure, means responsive to the water level in thesupply tankfor regulating admission of water thereto from said sourceand for normally maintaining" thewater in said supply tank at apredeterminedlevel therein, a switch controlling said heating means, andoperating connections between said regulating means and said switchacting to open the switch when the water inthe supply tank fallsmaterially below said predetermined level and to close said switch whenthe Water in saidlsupply tank is restored to said predetermined leveltherein.

Iii-sterilizing means; asterilizing tank, heat-- ing means therefbr, asource of supply of water under? pressure communicating with said tank,means: responsive to' -the' water level in the tank top regulatingadmission of waterfrom said source and normally maintaining the water insaidtank at; apredetermined level therein, a switch controlling saidheating means, and connectlons between the regulatingmeans'andsaidswitch-actingto open the switch when the water in the tankfalls materially below said predeten mined level and toclose'saidswitch-when the water in the tank isrestored-tosaid-predetermined level therein-3 8 I'n sterilizingmeans, asterilizing tank, elec-- trical heating meanstherefor, a water supplytankicommunicatingwiththe sterilizing tankfor supplying water thereto, awater admission pipe openingintcrsa-id water supply tank, a valvecontrolling said pipe', float means-responsive to-the water level in thewater tank and operatively

